CXCL8 and chronic periodontitis: However, Afro-Brazilians who were homozygous or heterozygous for the -67T>C SNP in the 5 ́ untranslated region of the FY gene and also had the IL8 -353A SNP (high producer of IL-8) were resistant to chronic periodontitis (p-value = 0.032; OR = 0.25; 95% CI = 0.078-0.79).